Process for purifying sugar solutions

Abstract

A process for decolorizing and demineralizing a sugar solution without the need for using cation exchange resins or activated carbon. The process includes the steps of contacting the sugar solution with a macroporous polymeric adsorbent having cationic functional sites to decolorize and demineralize the sugar solution, and contacting the sugar solution with an anion exchange resin to further demineralize the sugar solution.

What is claimed is: 
     
       1. A process for decolorizing and demineralizing a sugar solution, said process comprising the steps of: (a) contacting said sugar solution with a macroporous polymeric adsorbent having cationic functional sites to decolorize and demineralize said sugar solution; and   (b) contacting said sugar solution with an anion exchange resin to further demineralize said sugar solution,   wherein said process is carried out without an additional step of contacting said sugar solution with a cation exchange resin.   
     
     
       2. The process according to claim 1, wherein said sugar solution is a solution of fruit juice, fructose, sucrose, dextrose, sorbitol, or corn syrup. 
     
     
       3. The process according to claim 1, wherein said macroporous polymeric adsorbent having cationic functional sites swells less than 5% of its dry volume upon contact with said sugar solution. 
     
     
       4. The process according to claim 1, wherein said macroporous polymeric adsorbent having cationic functional sites is a copolymer of styrene and divinylbenzene. 
     
     
       5. The process according to claim 1, wherein said macroporous polymeric adsorbent having cationic functional sites has a surface area of about 900 to about 1100 m 2  /g, a pore volume of about 1 to about 1.1 ml/g, and an average pore diameter of about 850 to about 950 Å. 
     
     
       6. The process according to claim 1, wherein said anion exchange resin additionally removes color bodies from said sugar solution. 
     
     
       7. A process for decolorizing and demineralizing a sugar solution, said process comprising the steps of: (a) contacting said sugar solution with a macroporous polymeric adsorbent having cationic functional sites to decolorize and demineralize said sugar solution; and   (b) contacting said sugar solution with a macroporous polymeric adsorbent having anionic functional sites to further demineralize said sugar solution.   
     
     
       8. The process according to claim 7, wherein said sugar solution is a solution of fruit juice, fructose, sucrose, dextrose, sorbitol, or corn syrup. 
     
     
       9. The process according to claim 7, wherein said macroporous polymeric adsorbent having cationic functional sites has a surface area of about 900 to about 1100 m 2  /g, a pore volume of about 1 to about 1.1 ml/g, and an average pore diameter of about 850 to about 950 Å. 
     
     
       10. The process according to claim 7, wherein said macroporous polymeric adsorbent having anionic functional sites has a surface area of about 1000 to about 1500 m 2  /g, a pore volume of about 0.2 to about 0.4 ml/g, and an average pore volume of about 25 to about 100 Å. 
     
     
       11. The process according to claim 7, wherein said process is carried out without an additional step of contacting said sugar solution with a cation exchange resin. 
     
     
       12. The process according to claim 7, wherein said macroporous polymeric adsorbent having anionic functional sites additionally removes color bodies from said sugar solution. 
     
     
       13. The process according to claim 7, wherein said macroporous polymeric adsorbent having cationic functional sites and said macroporous polymeric adsorbent having anionic functional sites swell less than 5% of their dry volume upon contact with said sugar solution. 
     
     
       14. The process according to claim 7, wherein said macroporous polymeric adsorbent having cationic functional sites and said macroporous polymeric adsorbent having anionic functional sites are made of a copolymer of styrene and divinylbenzene.